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Costimulatory Function of CD28 in Avian γδ T Cells is Evolutionarily Conserved
Author(s) -
Satu Koskela,
Arstila,
Lassila
Publication year - 1998
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1046/j.1365-3083.1998.00441.x
Subject(s) - cd28 , t cell , il 2 receptor , biology , major histocompatibility complex , polyclonal antibodies , cd8 , microbiology and biotechnology , cytotoxic t cell , antigen , immunology , immune system , genetics , in vitro
CD28 costimulatory signals are required for T‐cell proliferation and lymphokine production. In this work, the functional conservation of CD28 was studied in avian γδ T cells. The avian CD28 molecule is expressed on all αβ T cells and is capable of giving a costimulatory signal. Most peripheral γδ T cells are CD28 negative; however, we identified a CD28‐positive γδ T‐cell subset from peripheral blood comprising about 12% of γδ T cells. The peripheral CD28 + γδ T‐cell subset included all CD8 + γδ T cells known to be a responding subset during activation. After polyclonal activation, the frequency of CD28 + γδ T cells was increased and the activation also up‐regulated CD5, CD25 and major histocompatibility complex (MHC) class II molecules. These changes were detected after both polyclonal and antigen‐specific T‐cell activation. In addition, we also showed that CD28 can give a costimulatory signal to γδ T cells and that this signal leads to up‐regulation of IL‐2 and bcl‐x transcripts. These results indicate that the function of CD28 is evolutionarily conserved and can already be detected in avian γδ T cells.